Proof output retention Phase 3: resume, supervisor, and disk ergonomics

[tonyketcham]

Summary

Make resumed Proof runs reconstruct execution transcripts with a versioned state schema and clear supervisor ergonomics.

Source Context

• Cursor cloud-agent follow-up: https://cursor.com/agents/bc-51322132-f3a3-4f80-b0cd-0ed319ccce62
• Implementation PR: docs: plan proof output retention #199
• Proposal artifact: https://github.com/FlatbreadLabs/flatbread/blob/toeknee/proof-output-retention-ce62/docs/proposals/proof-output-retention-plan.md
• Review artifact: https://github.com/FlatbreadLabs/flatbread/blob/toeknee/proof-output-retention-ce62/docs/proposals/proof-output-retention-review.md
• Judge artifact: https://github.com/FlatbreadLabs/flatbread/blob/toeknee/proof-output-retention-ce62/docs/proposals/proof-output-retention-judge.md
• Phase-specific artifact section: https://github.com/FlatbreadLabs/flatbread/blob/toeknee/proof-output-retention-ce62/docs/proposals/proof-output-retention-plan.md#L257-L279

Why This Exists

• Phase 1 can reconstruct task transcripts after restart only when the same artifact directory is reused and transcriptPath points at a stream mirror.
• The proposal's Phase 3 makes that behavior explicit with a versioned persisted-state transcript union and testable input parity across runner restarts.
• The review highlights the current silent-degradation edge when a supervisor restarts into a fresh timestamped artifact directory; Phase 3 should turn that into a documented and noisy operator path.

Acceptance Criteria

• Bump PersistedRunState to version: 2 with transcript: { kind: 'artifact' | 'inline' | 'legacy', ... } per the proposal.
• Teach resume loading to rebuild the transcript store from artifact pointers or gzipped inline data before any resumed rank executes.
• Preserve one-release compatibility for version: 1 state by promoting legacy resultText into the new transcript shape.
• Add supervisor warning/validation for restart-on-runner-change runs that do not pin --full-output-dir, especially when artifacts are disabled or missing.
• Add deterministic input-parity, state-size, migration, and supervisor-warning tests.

Verification

• pnpm -F @flatbread/proof test
• pnpm -F @flatbread/proof typecheck
• pnpm verify

Related Phase Issues

• Proof output retention: Phase 0/1 follow-up hardening #200 — Proof output retention: Phase 0/1 follow-up hardening: Proof output retention: Phase 0/1 follow-up hardening #200
• Proof output retention Phase 2: upstream prompt policy and budget preflight #201 — Proof output retention Phase 2: upstream prompt policy and budget preflight: Proof output retention Phase 2: upstream prompt policy and budget preflight #201
• Proof output retention Phase 3: resume, supervisor, and disk ergonomics #202 — Proof output retention Phase 3: resume, supervisor, and disk ergonomics: Proof output retention Phase 3: resume, supervisor, and disk ergonomics #202
• Proof output retention Phase 4: oracle evidence alignment #203 — Proof output retention Phase 4: oracle evidence alignment: Proof output retention Phase 4: oracle evidence alignment #203
• Proof output retention Phase 5: documentation and skill refresh #204 — Proof output retention Phase 5: documentation and skill refresh: Proof output retention Phase 5: documentation and skill refresh #204

Artifact Linkage

This issue is linked back from docs/proposals/proof-output-retention-plan.md and, where relevant, docs/proposals/proof-output-retention-review.md so the repo artifacts and GitHub issues remain navigable in both directions.